With growing marijuana, you sometimes come upon various insects in the garden from time to time.
One such insect the root aphid which is becoming a increasing problem with growers more frequently.
Root aphids can cause some serious damage to your cannabis plants if not taken care of soon enough.
Because once you start to flower it will become even harder to eradicate these pests, without comprising your buds.
A species of these little bastards also caused a great devastation to the wine industry in France in the 19th century.
So it’s good to take note these insects are major threat.
What is a Root Aphid?
The root aphid is part of the Phylloxera family tree, more specifically Phylloxeridae.
I know I cannot pronounce them myself, but in a nutshell, there are many species wrapped up in this gene pool.
They are all plant parasites, which means they feed off the roots of all types of plants.
Lets take a closer look,
The root aphid is asexual meaning they always reproduce female offspring. The aphid can produce up to 60 -100 nymphs in 20 to 30 days.
Or in anywhere from 7- 10 days. As noted from the University of Massachusetts Amherst.
Root Aphid vs Fungus Gnat
There is a noticeable difference between the root aphid and fungus gnat if you are unsure of what is doing damage to your marijuana plants.
Root Aphid
Fungus Gnat
Root aphids are short and stocky and usually cannot fly far.
Fungus gnats are long lanky and usually black.
The aphid is also mistaken for mealy bugs around the roots and surrounding areas. Note they are usually smaller.
Signs of Root Aphid Invasion
The symptoms of root aphids have infested your cannabis plants can be, the plants will start to have yellowing leaves and appear to have stunted growth. It can resemble a magnesium deficiency.
! Make sure your plant is getting enough magnesium.
Another sign is you may notice them crawling around the top of the soil or on some of the bottom leaves.
Cause of Root Aphids in Cannabis Plants
The main reason why you may have aphids can be due to many factors.
- Bringing outside plants in from stores or gardens to your house
- Over-watering your plants can lead to a more suitable environment for the root aphids to lay their eggs,
- Soil purchased that is mass produced can possible harbor some the aphids from the beginning, and you may never know until it is too late.
- Not taking care of your hydroponic system, with rock wool and coco coir on upkeep and maintenance.
- By going unchecked, they can all of a sudden spring out of nowhere
Best ways to Kill Root Aphids in Marijuana
Seeing as the aphids love the roots so much the best way to get rid of the aphids is to attack the source.
There are many ways to do this by using some natural remedies, organic solutions, and even some insecticides if you want to go all out.
Natural Remedies
Sand is a good preventive technique to use if you are using soil or coco coir as a growing medium.
Sand is like glass and stops them from going into your roots! Place about 1-2 inches on the top and bottom of your grow pots.
Just like the fungus gnat that has made its way to the roots, you can tackle this problem is the same manner.
If you have dealt with fungus gnats in the past you may already have some of these solutions on hand!
Landscape fabric is great a preventing aphids from invading your plants.
It is a barrier that they cannot penetrate easily.
One of the best ways to use landscape fabric for aphids is to put a cut out of it in the bottom of your pots when growing in soil or coco coir.
Simple trace out the top part of the pot and make a cutting for two pieces of fabric.
Place one circle cutting in the bottom of the pot and fill with grow medium so the side of the fabric a pressed against the edge of the pot.
Next place a cut out circle with a cut halfway to the center to wrap around the stock.
Then put some gnat nix or sand or additional grow medium on top this way it prevents them from coming in from the top or bottom of your cannabis plants.
Growstone gnat nix not only works for gnats but it also works for root aphids.
This recycled glass product is a great top / bottom dressing to be used to fight theses pest.
Your can put a layer of gnat nix in the bottom of your grow pots and then fill with medium after planting your seedling or clones .
Or transplanting your marijuana plants place a layer of gnat nix on top .
One note is that Grow stone is going out of business and it is getting harder to find gnat nix around if you do find it stock up!
Yellow sticky trap paper is a great first defense it starts to kill the adult and nymphs hopefully before they can reproduce.
Beneficial Nematodes work well in either soil or hydroponic systems the used rock wool or coco coir and even aquaponics.
You just add these to water, and they go to work.
I cannot recommend Beneficial Nematodes enough.
Beneficial Nematodes are good at killing root aphids and so many different types of insects like fungus gnats.
It’s easy to apply. I usually add them after transplanting about two weeks later.
Neem Oil is an excellent natural remedy that works on all type of insects and fungal outbreaks. Make sure the soil is completely dry.
Simply mix two tablespoons per gallon of water and soak the roots of your plants.
Diatomaceous Earth is another great alternative. It’s a food supplement that is also a root eating insect killer!
Diatomaceous Earth contains silica which is made up of fossilized remains of aquatics creatures. This makes like a glass wall so root aphids can’t lay the eggs that feed off the roots .
Great results have been seen in two weeks or less.
For proper handling here is a resource from: The International Diatomite Producers Association (IDPA).
Insecticidal Soap can be used to stop the root aphids. Instead of spraying the leaves of your plants it is best to give it a good spray on the top soil.
The soap is great at killing on contact these buggers.
One thing is that if you do spray the top part of the grow medium is that it will have to be treated again after feeding.
It’s best to add a layer of landscape fabric with sand of more grow medium to prevent them from becoming adults and flying out to infect more of your plants.
The insecticidal soap can also be sprayed on the leaves of plants , but usually the root aphids visible on the top of growing mediums
Stratiolaelaps scimitus (soil mites) is another way to prevent and eradicate the root aphids.
This was mentioned from our reader Adam in the comments.
Soil mites are used by commercial growers to prevent and remove any type of insect such as gnats, mites, thrips.
You can also get these from Amazon. I would not recommend for indoor growing.
Dalotia coriaria (rove beetles) is also a way to prevent and remove these insects, used by commercial growers. I would not recommend for indoor growing.
More Extreme Remedies
Botanigard ES is something that is quite expensive, but it does the job. This stuff is nasty to the aphid it fills the larvae with a fungus and kills it.
If you need the final solution then this is your ticket.
Azamax is a great second alternative after natural remedies; it is 100 percent vegetable base solution that is made for all insects chewing and sucking.
Can be used in foliar sprays or when watering plants.
Azatrol a food grade insecticide that works ideal for hydroponic tanks and is perfect for soaking the soil when you have an outbreak.
Azatrol kills the larvae of aphids.
Evergreen Pyrethrin is the total package, it’s a broad spectrum insecticide, and takes care of a lot of insects. From aphids to the Japanese Beetle.
Pyrethrin is made from the flower of the chrysanthemum.
Not recommended for outdoor growing it’s bad for the bees when sprayed.
Go light on soaking your plants with this stuff.
Recommended dose 1-3 ml/gallon
Organocide is a natural 3 in 1 solution a insecticide, fungicide, miticide.
This could be used as an effective way to get rid of aphids larvae and any other problem in your garden.
Check out the video to see how to get rid of aphids,
With so many solutions which one should you choose?
It all depends on maybe what you have around the house or you can go a little more extreme.
My personal favorite preventive measures is beneficial nematodes with landscape fabric, yellow sticky paper and either some Insecticidal soap or Organocide when I need to eradicate these root eaters.
The root aphid is destructive if they get out of hand.
So if you use some preventive techniques such as sand and beneficial nematodes.
Control the grow space with temperature and humidity and not over watering your mediums.
You should make out alright in destroying those nasty root aphids in your cannabis plants.
Let me know in the comments how you made out or what works for you.
Grow on my friends
Thanks for the info man – I caught them at an earlier stage, where I only see them in some pots and not all… and there are no flying ones around just around the root zone, little white and small red one munching on my roots. I am going to try out some of these remedies.
Hey Jai
That’s awesome you caught them early! I am glad this post helped you out, let me know how it goes.
Diatomaceous Earth. I wish I had known it was such a great preventative before I started. Apparently this stuff is like a bulletproof wall of microscopic glass. I’ve read a lot of people say to top dress, bottom dress, heck all over the pots and along the sideboards. Many mix it with soil! It onl works when dry, but it also provides minerals and helps with nutrient uptake! Best of all, it cheap!! Read about some of the dangers of handling improperly before you dive in. I hope this saves at least one person from the pain it has brought to me. Good luck
Hi RJ,
Yeah Diatomaceous Earth is really good for the root eaters. I agree you do have to be careful when handling the stuff. I have put a link in the post for proper handling procedures. Check it out if you ever need reference. It’s from the actual producers of the stuff.
Man I’m having issues with the bastards not seeing flyers but they are in my flower/veg room I’m scared to flip I’ve been using og biowar would you say mycotrol by botainigard is stronger
Justin,
Yes Mycotrol by botainigard is stronger than og bio war.
I would recommend : BotaniGard 22WP Biological Insecticide
Its recommended in Canada by Health Canada for the Licensed Producers for Medical Marijuana.
Its a little expensive but should help you out.
After a route drench with this would you just want water regularly with Nutrients or do a plain water first
Go back to using your nutrients again. The plants will need it.
WOW. I grew up in a cotton field. Weevils I knew how to deal with. Have planted grapes 2 years ago and since I really wasn’t looking the plants closely until the third year, guess what I found? I feel like the French. The root aphids have completely inendated my plant. Trying not to panic (not shopping for toads yet.) Going straight for high doses of Botanigard ES. I’ll let you know how things work out.
Hi David,
No need to panic.. No toads required. That Botanigard should solve all your problems with these root eaters.
All you people are crazy. Nothing kills these little bastards. I lined up 10 different treatments un 10 different bottle caps and put a different treatment in each cap along with a piece of rootball infested with the aphids. In all treatments but two, was there a single aphid that was dead when I looked over 12 hours later. I mean i put enough treatment drowning them I thought. They were all swimming around, having a party. The only two killed all or most of them, was evergreen and assiphate. Even they didn’t kill them all. Microtrol does not work, most enzymes do not work and most of all, the one whom I strongly suggest no using, is imidacloprid of any type. It has something to do with the red drarwf barely virus or any and every virus known to man.
Evergreen concentrated pyrethrum in a soil drench is my weapon of choice for a knockdown. We go pretty light on it (1-3 ml/gallon), but it’s incredibly effective. Don’t waste your time with Botaniguard. It’s expensive and not effective at stopping an infestation. Botaniguard works well in combination with nematodes and soil mites preventatively, but if you find an infestation, especially if it’s heavy, nuke them with pyrethrum.
Hi Micheal,
Thanks for mentioning Evergreen Pyrethrum, I looked further into the stuff , used on organics and made from the chrysanthemum flower. Pretty cool. I am adding to the list. I will definitely consider this in the future.
Been battling root aphids for quite some time now and beneficial microbes and fungi is just not enough for the battle. I’m going to first add some nematodes. Within 2-3 days I’m going to start using an IPM program. Azamax, Botanigard, and evergreen are going to be using every 1-2 weeks from now how. Hopefully that’ll wipe out my problem for good!
Hi Micheal,
Yeah those root aphids can be ruthless, those nematodes should work, maybe with some sand on top of your soil or coco after , and azamax. See what happens in a week. Then go for the evergreen. and botanigard. Your plan should get rid of these buggers !
I have fought these things twice. The first time they won, I cut everything down and moved 2k miles. It worked. No más. Now I got them from storing my plants at a friends during a power outage. This is what I’ve done this far. I hope it helps someone. PS-Growing in Rockwool. First I did a .5 strength greencleaner dunk soaking the unislab and block. I left them in that for probably 5 minutes or until none were moving. Then I rinsed the oil from the roots with RO water. I then immediately dunked them the same way in botanigard es @ 10ml/Gal. I only used the green cleaner for the initial treatment but followed up every other day soaking in botanigard es for two more treatments. I waited 5 days and did another botanigard es dunk. Before the last treatment I only saw a few moving. Most dead. After treatment zero movement. My plants did not particularly like these treatments, but it did not slow them down like with Bayer and other chems I tried the first time. Took about 5 days for them to completely recover. I always recommend throwing them out and starting over once you see them but sometimes that’s just not possible. I also would like to mention that I caught them before flying. Once they are flying, game over, you lose, they win. Throw everything out, bomb, bleach your room, and start over. I hope this helps. I don’t know if botanigard es will completely kill them all, but will def slow them down big time with very little side effects.
Thanks for the info WW
Thanks for the Great article,
I just delt with these bastards they took down my whole crop unfortunately. My question is what product is good to add to my weekly mix that I can feed with my other nuts as a provenitive, without having to do a whole flush every time. I don’t mind using some hardcore stuff over the organic methothds since now I know what these guys can do.
Thanks.
Hi Justin ,
I can really only recommend beneficial nemotodes as a preventive , and not any hardcore stuff when feeding your plants and nutes at the same time, maybe put a thin layer of sand or diatomaceous earth to stop them from invdading and setting up shop in your root zone.
I have the instant Solution 1 time fix for root aphids! I was having a problem with Root Aphids, noticed first by stunted growth, then my new leaves were coming in with less points (9 pointed leaves to 7, and i even saw some 5, and 3 pointed leaves) next i examined the soil to find very tiny almost pin head sized bugs crawling in the top of my soil, i examined the roots and seen a slightly larger rounder aphid munching away! I went to my local Hydroponic/Gardening store and the man at the front recommends Intercept 60WP (Lable said for use on vegetables so i knew it was safe for my plant and me) its a Soil Drench that you only have to use once! After doing my drench 4-6 hours later i examined my soil to find nothing crawling around anymore and havnt had a problem since! (Mixing Ratio is 1g/5L Water! My Soil Pot holds 20L of soil) it comes in a powder that easily mixes into water but has no strong odor and chemical smell! My store scaled out the 1G needed for $15 Canadian so it was extremely affordable and got the job done perfectly! I hope this helps someone who had the same problem as me!
Hi Eli,
Great to know Intercept 60WP will do the job , It’s awesome you were able to defeat the root aphids. I will keep it in mind for next time .
intercept 60wp
is imidacloprid.
DO NOT USE on cannabis
900 day half life….
Update: No small little Crawlers in the soil, but im still seeing some adult winged aphids popping up! What should i do?
Hi Eli,
I know this is la little late reply,sorry he comment never showed up as a new comment. Best to use some yellow sticky trap paper and also try and narrow down the source. Which may be outside your garden.
intercept 60 wp only available in Canada. Wish I could get some in the US Botanigard es is low dose. the powder 22wp is 22% the es is 1.7 % if I read the label right. I’m going for the 22% . And evergreen pyrethrums 5%
I went light with just the DE and Evergreen this year.I will be digging all my holes out to virgin sand after the season is over.DE in the holes and mixed with new soil , nematodes, Botanigard 22wp, azamax, and sand and De on top. did I forget something?
fuck them buggers. Lost 3 last year and 4 this one.
Hi John,
I think you got it covered for the new season. I feel your pain , these root aphids are ruthless. Hopefully next season will be better for you.
Could you explain the difference in Botanigard ES and Botanigard 22wp I got the 22WP but in reading more …..The ES is listed for root aphids ,but the 22wp lists aphids but not specifically root aphids. Help me out . is the 22 ok or do I need the ES. thanks john
Hi John,
The only difference is one that you have is wet-table powder (WP) and the other is Emulsifiable Suspension (ES) meaning basically a condensed liquid form .
check out this pdf here : https://www.bioworksinc.com/products/shared/botanigard.pdf
Hope this helps.
You should be ok with the WP. good luck
Hi I have an orange dotting on tops of leaves only of what I believe is fungus. I found this and root aphids simultaneously. It Builds up and weakens/yellows small shoots and eventually turns them brownish black and dies. Has anyone seen this. Is this root aphid damage or rust?
Hi Rob,
I have not seen anything like that with root aphids, not to sure what that would be. If anyone has seen this issue post in the comments.
Could be a ph problem, Rob
Norman ,
That’s a great point, PH is the root cause of a lot of leaf issues. thanks for commenting
Thanks for this article it’s the best one I’ve found. Anyway, my question is. If I’m understanding this right. Diatomaceous Earth shreds these guys. So would adding both that and nemotoads be counterproductive? Wouldn’t the toads die as well? If that is the case. Is it use one or the other?
hi some guy,
Thanks for the comment it means a lot , really appreciate it. Your right, use one or the other and not both at the same time.
Don’t buy cheap store brand or off brand potting soils. Almost guaranteed to have at least one type of bug or virus in it. Keep your plants healthy and bugs won’t be a problem. Just like plants, bugs thrive when the conditions are right for them. Supplement with silica or add a handful of bentonite cat litter to a 5 gal. and make sure your supplementing Cal/Mag or adding Dolomite Lime to your soil as well, especially if you use R.O. water. Dissolve a tablespoon of bentonite cat litter (the grey CLAY clumping stuff… also called Aluminum Silicate) in water – it takes some mixing and mashing with a spoon, then add that to a 5 gallon of your regular water/nute solution. do this only when watering in after transplanting, so twice per season.
Thanks for sharing Steve . Great info !
Hey Parker great article!
I run a commercial cultivation facility up in Anchorage, Alaska and those bastards have made there way up north! Very excited to try some of these techniques asap. I found Mighty Wash to be a great product for killing on contact when things get out of hand.
Hi Brady,
I am happy you liked the article. Alaska is a beautiful place. Good luck eradicating these pests. Happy hunting.
Hey, thanks for the great info. Can Organocide be used all the way through flowering?
Hi JIm,
I have not used organocide in flower. I would say use at your own risk, maybe try on one plant and see what happens.
Hey how are you doing? Just have a question. I am battling these little @×$% suckers and got merit 75. Is it ok to attack with only this or will they become immune to it?
Merit 75 is pretty strong, not sure if they would or not.
I’ve been battling these suckers for weeks now my clones are still in solo cups after 2 months ! my roots arent growing and i’ve been using neem oil , should I be more aggressive and use nematodes and azamax ?
If it has been that long I would start over. You could try a thin layer of sand on top of the grow medium.
Not mentioned here is actually the more suitable natural predators Stratiolaelaps scimitus (soil mites) and Dalotia coriaria (rove beetles). These are what commercial growers will introduce early on for protection, for the life of the crop, from fungus gnats, root aphids, pupating thrips, diapausing spider mite, etc. These persist and will give control where nematodes are cheap and effective at doing a knockdown but will not give control. If you want to go with natural predators, try a knockdown with beneficial nematodes, then introduce Stratiolaelaps (if soil) or Stratiolaelaps and Dalotia (if DWC) to maintain control.
Nice article and good collection of information. Thanks!
Thanks Adam, I have added your info to the post!
Will monterey garden insect spray, ( spinosad ) kill aphids and fungus gnats?
it could i have not tried it , I know it kills thrips and other pests
Any advice on how to decontaminate a grow tent after having root aphid infestation?
Spray with an alcohol water mix solution, also take a vacuum to other corners of tent and bottom insert if your tent has that. Check the rest of your house! The gnats may be in another plant .
Dude I’m away working and I have this full automated grow system worked out so anyways I got my buddy to go check my plant and he said he killed like 12 adult root aphids and plus one plant looks unhealthy But my but the other looks healthy. do u think it’s to late For both of them like he hasn’t saw any nymphs but do they borrow into the root
That sucks Dvon, Have your buddy setup some yellow stick y tapes around the bottom of the plants , the root aphids do not burrow into the roots itself they eat the roots, and live in the grow medium . May not be to late if youro using a grow medium you can also spray the tops of the medium with insecticidal soap may help. Also check out some other solutions..
Can someone describe in detail how they do/did the soil drench treatment with Evergreen Pyrethrum?
I understand you add 1-3ml of Py for every gallon of water. Do you then water the plant until you see runoff? If there’s a special technique such as watering the stem since they seem to hide under the main stem. Do you treat it a second time, if so when?
Thanks!
Hi David, you want to drench the soil but not till run off. do it 2 times 5 days apart . try that out . Also you are right about the main stem/ main tap root. there will be an “umbrella effect ” so be sure to soak it well and start at the the main stem.
Soil drench with 48 – 50 degrees Celsius water temperature for 10 minutes will kill them all. You will see them all floating dead in your drench water. If you have a lot to do, find a “au bain marie” big enough for your pots/trays.
Even better measure temp in rootball till it reacties 46 degrees.
Drench in normal temperature water direclty afterwards
Move. Start over from seed. Lots more. Good luck.